Stellar Death: White Dwarfs, Neutron Stars and Black Holes · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

What dead stars leave behind

Science · Astronomy & Astrophysics · ages 21-22
Name ______________________   Date ____________
  1. How does degeneracy pressure respond to cooling?

    • It does not depend on temperature
    • It fades as the star cools
    • It grows only while fusion runs
  2. What holds up a white dwarf?

    • Ongoing fusion in its core
    • Electron degeneracy pressure
    • Heat from its surface
  3. Above about how many solar masses does electron degeneracy fail?

    Answer: ______________

  4. A remnant of 2 solar masses remains after a supernova. What is it?

    • A white dwarf
    • A planet
    • A neutron star
  5. A remnant of 0.6 solar masses cools quietly. What is it?

    • A neutron star
    • A black hole
    • A white dwarf
  6. How does a core collapse supernova spread heavy elements?

    • It locks every atom inside the remnant
    • It blasts the envelope outward into space
    • It burns heavy atoms back into hydrogen
  7. Why does an iron core bring support to an end within seconds?

    • Iron fusion absorbs energy instead of releasing it
    • Iron is too light to feel gravity
    • Iron blocks all light from escaping
  8. A student says a 5 solar mass core settles as a neutron star. What is wrong?

    • Neutron stars cannot form in supernovae
    • Past about 3 solar masses nothing stops the collapse
    • Cores that heavy always explode completely
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Answer key

For grown-ups. Fold this page away before handing over the rest.

What dead stars leave behind W1-mt_k1oUF3mJlu-s1

  1. It does not depend on temperature · Quantum crowding cares about density, not heat.
  2. Electron degeneracy pressure · No fusion runs there; quantum crowding resists the squeeze.
  3. 1.4 · Past 1.4 solar masses, collapse continues beyond a white dwarf.
  4. A neutron star · Past the white dwarf ceiling but below 3, neutrons hold it up.
  5. A white dwarf · Far below the 1.4 ceiling, degeneracy holds it as a white dwarf.
  6. It blasts the envelope outward into space · The rebounding blast carries the forged elements outward.
  7. Iron fusion absorbs energy instead of releasing it · With no fresh energy pushing out, the core implodes at once.
  8. Past about 3 solar masses nothing stops the collapse · At 5 solar masses the collapse runs past neutron matter into a black hole.
Worksheet · LightMySky